create-skill

create-skill is a skill for Claude Code, Codex from Agent-Threat-Rule/agent-threat-rules. It costs 61 tokens per session (1,294 once invoked), scanned A, a copy of create-skill, MIT.

A workflow for creating a new reusable agent skill, including its description, files, instructions, supporting resources, and validation. An agent skill is a packaged set of guidance that helps a coding agent perform a particular kind of task.

In plain words
What is it for?
Use it to scaffold a new `SKILL.md`, choose how its information is revealed, add resources, and validate the result.
Why use it?
It provides a structured way to turn a task into a consistent skill instead of assembling the files and instructions ad hoc.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to scaffold a new SKILL.md, choose how its information is revealed, add resources, and validate the result.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/agent-threat-rule/agent-threat-rules/create
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add Agent-Threat-Rule/agent-threat-rules --skill create
Clone the repo
git clone --depth 1 https://github.com/Agent-Threat-Rule/agent-threat-rules

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for create-skill

README.md
[![agentmods](https://agentmods.dev/badge/skills/agent-threat-rule/agent-threat-rules/create.svg)](https://agentmods.dev/skills/agent-threat-rule/agent-threat-rules/create)
Your own site
<a href="https://agentmods.dev/skills/agent-threat-rule/agent-threat-rules/create"><img src="https://agentmods.dev/badge/skills/agent-threat-rule/agent-threat-rules/create.svg" alt="Measured on agentmods" height="20"></a>
Per session 61 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,294 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00061 $0.01294
Opus 5 $0.00030 $0.00647
Sonnet 5 $0.00012 $0.00259
Haiku 4.5 $0.00006 $0.00129

Measured 2d ago against content hash c2188e8a0a66, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

create-skill scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to create-skill — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

data/skills-sh/skills/hyf0/create-skill.md · 125 lines

How it starts

The opening of the file, as written. The whole thing — 125 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Workflow

Follow these 9 steps in order. Copy this checklist into your response and check off each step as you complete it:

Task Progress:
- [ ] Step 1: Understand the skill with concrete examples
- [ ] Step 2: Choose skill name
- [ ] Step 3: Write description
- [ ] Step 4: Write frontmatter
- [ ] Step 5: Write SKILL.md body
- [ ] Step 6: Decide on progressive disclosure
- [ ] Step 7: Create bundled resources
- [ ] Step 8: Validate
- [ ] Step 9: Iterate

Step 1: Understand the Skill with Concrete Examples

Work through 2-3 concrete examples of how the skill will be used. Ask the user:

  • What does the skill do? Can you show me an example of how you'd use it?
  • What would a user say that should trigger this skill?
  • Does it need allowed-tools (does it run shell commands, use MCP tools)?
  • Should this be a background skill? (always-loaded context, not user-invocable — see frontmatter-spec for user-invocable: false)

For each example, walk through how it would be executed from scratch. This reveals what knowledge, scripts, or assets are needed.

Classify the skill category:

  • Document/asset creation — generates files, reports, configs
  • Workflow automation — multi-step processes, scaffolding, setup
  • MCP enhancement — extends or coordinates MCP server capabilities

Step 2: Choose Skill Name

Rules:

  • Gerund form for processes (creating-components), noun form for tools (code)
  • Kebab-case, max 64 characters, must match folder name

Step 3: Write the Description

This is the highest-impact field — a poor description causes the skill to never be invoked.

Follow the "What + When" formula and all rules in: -> See description-writing

Step 4: Write the Frontmatter

Use the exact YAML schema and constraints in: -> See frontmatter-spec

Step 5: Write the SKILL.md Body

Rules:

  • Under 500 lines (~5,000 words max)
  • Only include knowledge the agent does not already have — do not teach general programming, standard libraries, or well-known tools
  • No time-sensitive information (versions that expire, URLs that rot)
  • Consistent terminology throughout — pick one term for each concept and stick with it
  • Imperative voice
  • For any workflow with 3+ steps, include a copyable task list checklist (- [ ] items) that the agent copies and checks off as it progresses — this prevents step-skipping and makes progress observable
  • Match instruction specificity to task fragility — see "Degrees of Freedom" in skill-patterns

Read the full file on GitHub · 125 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 125 lines · 61 tokens per session scan A c2188e8a0a66

Subscribe to this mod's changes

create-skill is a skill published in the GitHub repository Agent-Threat-Rule/agent-threat-rules (385 stars, last pushed today), licensed MIT. It adds 61 tokens to every session and 1,294 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to create-skill, differing in 0 lines, and is treated as a copy.

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